ACTH test after adenomectomy may accurately predict Cushing’s disease remission

A plasma adrenocorticotropic hormone suppression test performed shortly after surgical adenomectomy may accurately predict both short- and long-term remission of Cushing’s disease, according to research published in Pituitary.

“Cushing’s disease is caused by hypersecretion of adrenocorticotropic hormone (ACTH) by a pituitary adenoma, resulting in hypercortisolism,” Erik Uvelius, MD, of the department of clinical sciences, Skåne University Hospital, Lund University, Sweden, and colleagues wrote in the study background. “Surgical adenomectomy is the first line of treatment. Postoperative remission is reported in 43% to 95% of cases depending on factors such as adenoma size, finding of pituitary adenoma on preoperative MRI and surgeons’ experience. However, there is no consensus on what laboratory assays and biochemical thresholds should be used in determining or predicting remission over time.”

In the study, the researchers retrospectively gathered data from medical records of 28 patients who presented with Cushing’s disease to Skåne University Hospital between November 1998 and December 2011, undergoing 45 transsphenoidal adenomectomies.

On postoperative days 2 and 3, oral betamethasone was administered (1 mg at 8 a.m., 0.5 mg at 2 p.m., and 0.5 mg at 8 p.m.). Researchers assessed plasma cortisol and plasma ACTH before betamethasone administration and again at 24 and 48 hours, and measured 24-urinary free cortisol on postoperative day 3.

At 3 months postoperatively and then annually, plasma concentrations of morning cortisol and ACTH along with urinary-free cortisol and/or a low-dose dexamethasone suppression test were evaluated at the endocrinologists’ discretion. The researchers defined remission as lessening of clinical signs and symptoms of hypercortisolism, as well as laboratory confirmation through the various tests.

The researchers used Youden’s index to establish the cutoff with the highest sensitivity and specificity in predicting remission over the short term (3 months) and long term (5 years or more). Clinical accuracy of the different tests was illustrated through the area under curve.

The study population consisted of mainly women (71%), with a median age of 49.5 years. No significant disparities were seen in age, sex or surgical technique between patients who underwent a primary procedure and those who underwent reoperation. Two of the patients were diagnosed with pituitary carcinoma and 11 had a macroadenoma. ACTH positivity was identified in all adenomas and pathologists confirmed two cases of ACTH-producing carcinomas.

Of the 28 patients, 12 (43%) demonstrated long-term remission at last follow-up. Three patients were not deemed in remission after primary surgery but were not considered eligible for additional surgical intervention, whereas 13 patients underwent 17 reoperations to address remaining disease or recurrence. Four patients demonstrated long-term remission after a second or third procedure, equaling 16 patients (57%) achieving long-term remission, according to the researchers.

The researchers found that both short- and long-term remission were most effectively predicted through plasma cortisol after 24 and 48 hours with betamethasone. A short-term remission cutoff of 107 nmol/L was predicted with a sensitivity of 0.85, specificity of 0.94 and a positive predictive value of 0.96 and AUC of 0.92 (95% CI, 0.85-1). A long-term remission cutoff of 49 nmol/L was predicted with a sensitivity of 0.94, specificity of 0.93, positive predictive value of 0.88 and AUC of 0.98 (95% CI, 0.95-1). This cutoff was close to the suppression cutoff for the diagnosis of Cushing’s disease, 50 nmol/L. The cutoff of 25 nmol/L showed that the use of such a strict suppression cutoff would cause a low level of true positives and a higher occurrence of false negatives, according to the researchers.

“A 48 h 2 mg/day betamethasone suppression test day 2 and 3 after transsphenoidal surgery of Cushing’s disease could safely predict short- and long-term remission with high accuracy,” the researchers wrote. “Plasma cortisol after 24 hours of suppression showed the best accuracy in predicting 5 years’ remission. Until consensus on remission criteria, it is still the endocrinologists’ combined assessment that defines remission.” – by Jennifer Byrne

DisclosuresThe authors report no relevant financial disclosures.

From https://www.healio.com/endocrinology/neuroendocrinology/news/in-the-journals/%7B0fdfb7b0-e418-4b53-b59d-1ffa3f7b8cd3%7D/acth-test-after-adenomectomy-may-accurately-predict-cushings-disease-remission

Radiation to the Whole Pituitary Compartment Effective at Controlling Cushing’s

Radiation therapy targeting the entire sella — the compartment where the pituitary gland resides at the base of the brain — is effective at controlling Cushing’s disease and should be considered for patients with suspected invasive adenoma tumors, a new study shows.

The study, “Technique of Whole-Sellar Stereotactic Radiosurgery for Cushing’s Disease: Results from a Multicenter, International Cohort Study,” was published in the journal World Neurosurgery.

In patients with Cushing’s disease, excess cortisol levels are caused by a kind of pituitary tumor (adenoma)  that secretes too much adrenocorticotropic hormone (ACTH).

Removing the adenoma using the transsphenoidal approach — a minimally invasive procedure performed through the nose to remove pituitary tumors — remains the first-line treatment for patients with newly diagnosed Cushing’s syndrome. For patients who fail surgery and medical management, stereotactic radiosurgery (SRS) may be used.

SRS is not a surgery in the traditional sense, as it does not require an incision. Instead, SRS uses many focused radiation beams to treat tumors and other problems in the brain, neck and other parts of the body.

While surgery may achieve very good remission rates in patients with an identifiable adenoma, as many as 50 percent of Cushing’s disease patients have no identifiable adenoma on magnetic resonance imaging (MRI) scans. In such cases, surgeons can opt for SRS targeting the entire sella, a procedure called whole-sellar SRS. However, the outcomes of whole-sellar SRS are not fully known.

Researchers conducted an international, retrospective study to analyze the outcomes of Cushing’s disease patients who received whole-sellar SRS.

The study enrolled 68 patients, including 52 who received the procedure for persistent disease, nine whose disease returned after surgery, and seven as their initial treatment.

Patients underwent a type of SRS known as gamma knife radiosurgery (GKRS), which uses small beams of gamma rays to target and treat brain tumors. They were then followed for a mean of 5.3 years.

Whole-sellar SRS was effective at controlling the disease, researchers found. In the five years after receiving the treatment, 75.9 percent of patients achieved a remission. Of those, 86% remained recurrence-free for five or more years.

The mean volume of area targeted using whole-sellar SRS was 2.6 cm3. Researchers discovered that treatment volumes greater than 1.6 cm3 were associated with a shorter time to remission, indicating that targeting a larger portion is more beneficial.

Also, statistical analysis revealed that a reduced dose of radiation was linked to recurrence, suggesting that a higher dose is more advantageous.

Regarding adverse events, 22.7% of patients who underwent whole-sellar SRS developed loss of one or more pituitary hormones.

Researchers also compared outcomes of patients who underwent whole-sellar SRS to those who received adenoma-targeted SRS, of which the latter involves irradiating only the tumor.

Interestingly, there were no differences in remission rate, time to remission, recurrence-free survival, or new endocrine disease development between both groups.

“Whole-sellar GKRS is effective at controlling [Cushing’s disease] when an adenoma is not clearly defined on imaging or when an invasive adenoma is suspected at the time of initial surgery,” the researchers concluded.

From https://cushingsdiseasenews.com/2018/05/25/precise-radiation-pituitary-sella-effective-control-cushings-study/

High Levels of MMP-9 Enzyme May Predict Tumor Recurrence in Cushing’s Patients

Measuring the levels of a specific enzyme in pituitary tumors producing excess adrenocorticotrophic hormone (ACTH) may help predict the recurrence of Cushing’s disease in patients, a study shows.

The study, “Expression of MMP-9, PTTG, HMGA2, and Ki-67 in ACTH-secreting pituitary tumors and their association with tumor recurrence,” was published in the journal World Neurosurgery.

Cushing’s syndrome is characterized by excess cortisol levels in the blood. In 70 percent of cases, this is caused by pituitary tumors making too much ACTH, a hormone that regulates cortisol production. This condition is called Cushing’s disease.

While transsphenoidal adenomectomy, a surgery to remove a pituitary gland tumor, is the first treatment choice, tumor recurrence rates can be as high as 45 percent.

Only a few studies have investigated the association between biomarkers and the risk of ACTH-secreting pituitary tumors recurring, leaving physicians with limited methods to predict which patients will have a recurrence.

Identifying biomarkers that can effectively predict the potential recurrence of Cushing’s disease would allow clinicians to look for early signs in patients and start appropriate follow-up and therapeutic protocols, avoiding long-term mortality.

Many studies have suggested that matrix metalloproteinase-9 (MMP-9) enzymes, the pituitary tumor transforming gene (PTTG), and high mobility group A 2 proteins (HMGA2) all play vital roles in the development of pituitary tumors.

Metalloproteinases (MMPs) are enzymes that work to degrade the cell’s extracellular matrix, which anchors the cell, thus enabling tumor invasion. PTTG is highly expressed in pituitary tumors, and is a marker of malignancy in many types of tumors. HMGA2 is overexpressed in various tumors, and is also associated with high malignancy.

However, whether levels of MMP-9, PTTG, and HMGA2 are related to ACTH-secreting tumor recurrence has not been investigated.

Researchers set out to determine the expression levels of MMP-9, PTTG, HMGA2, and Ki-67 (a marker of cell growth) in ACTH-secreting pituitary tumors, and evaluate their association with tumor behavior and recurrence.

They conducted a retrospective study that included 55 patients with sporadic Cushing’s disease with long-term remission after a transsphenoidal adenomectomy. Their tumor specimens were collected and examined.

Patients were divided into two groups based on whether or not they had tumor recurrence. There were 28 patients in the non-recurrent group, and 27 in the recurrent.

Results showed there was significantly increased expression of MMP-9 in tumor samples of recurrent patients, compared with the non-recurrent group. Levels of MMP-9 were also strongly associated with a shorter time period to recurrence (recurrence-free interval).

On the other hand, PTTG, HMGA2, and Ki-67 expression was not significantly different between the recurrent group and the non-recurrent group.

“ACTH-secreting pituitary tumors with higher levels of MMP-9 were associated with a higher recurrence rate and a shorter recurrence-free interval. MMP-9 could be a valuable tool for predicting recurrence of ACTH-secreting pituitary tumors,” the researchers concluded.

From https://cushingsdiseasenews.com/2018/03/02/mmp-9-enzyme-levels-may-predict-tumor-recurrence-in-cushings-study/

Endoscopic and Microscopic Surgery Equally Effective in Cushing’s Disease

Using endoscopic or microscopic techniques to surgically remove the pituitary glands leads to similar remission and recurrence rates in Cushing’s disease patients, a review of 24 studies shows.

The study, titled “Outcome of endoscopic vs microsurgical transsphenoidal resection for Cushing’s disease,” was published in the journal Endocrine Connections.

In endoscopic transsphenoidal surgery, a surgeon uses a tiny camera as a guide, allowing for a panoramic surgical view with increased illumination of anatomic structures. In microsurgical transsphenoidal resection, a surgeon views through a microscope and uses minute instruments or lasers. Both procedures are used in transsphenoidal (TS) surgery to remove pituitary gland tumors, the root cause of Cushing’s disease. In transsphenoidal surgery, a surgeon accesses the pituitary gland through the nose and sinuses.

While endoscopic surgery seems to lead to better patient outcomes, it was unclear before this study if it has any advantages in patients with Cushing’s disease.

To gain more insight into the remission and recurrence rates of both techniques, researchers examined a total of 24 studies that included 1,670 adult patients with Cushing’s syndrome. Of these patients, 702 underwent endoscopic TS, and 968 underwent microsurgical TS.

The study’s authors found that remission rates were similar in both groups. In the endoscopic group, an average of 79.7 percent of patients experienced remission versus 76.9 percent in the microscopic group.

Patients who underwent endoscopic surgery experienced recurrence less often than those who underwent microscopic surgery, with recurrence rates of 11 percent and 15.9 percent, respectively. But researchers pointed out that follow-up times in the studies varied, making comparisons unreliable.

When recurrence rates were calculated by person per year, which takes follow-up time into account, both groups had a recurrence rate of approximately 4 percent per person per year.

Previous studies have shown that complications following either type of surgery occurred at comparable rates. These complications include hypothyroidism (underactivity of the thyroid gland), diabetes insipidus (a condition characterized by increased thirst), CSF leakage (leakage of fluid that normally bathes the brain and spinal cord), visual defects, hypocortisolemia (low cortisol blood levels), and hypogonadism (little or no hormones produced by the sex glands).

“We found that overall remission proportion was the same in CD patients who underwent endoscopic TS compared to patients who underwent microscopic TS. However, patients treated with the endoscopic approach for micro-adenomas were more likely to achieve remission than those treated microsurgically. Patients treated endoscopically were less likely to experience recurrence; however, when follow-up time is taken into account, this advantage disappears,” the researchers concluded.

 

From https://cushingsdiseasenews.com/2018/02/01/cushings-disease-transsphenoidal-surgery-study-finds-endoscopic-microscopic-procedures-equally-effective/

Temozolomide May Partially Improve Aggressive Pituitary Tumors Causing Cushing’s Disease

The chemotherapy temozolomide partially improved a case of an aggressive pituitary tumor that caused symptoms of Cushing’s disease (CD), according to a new study in Poland. However, after tumor mass and cortisol levels were stabilized for a few months, the patient experienced rapid progression, suggesting that new methods for extending the effects of temozolomide are needed.

The study, “Temozolomide therapy for aggressive pituitary Crooke’s cells corticotropinoma causing Cushing’s Disease: A case report with literature review,” appeared in the journal Endokrynologia Polska.

Aggressive pituitary tumors are usually invasive macroadenomas, or benign tumors larger than 10 mm.

A very rare subset of pituitary adenoma — particularly corticotropinoma, or tumors with excessive secretion of corticotropin (ACTH) — exhibit Crooke’s cells. These tumors are highly invasive, have a high recurrence rate, and are often resistant to treatment.

Information is not widely available about the effectiveness of treating aggressive pituitary tumors, particularly those that cause Cushing’s disease. The management of these tumors usually requires neurosurgery, followed by radiotherapy, and pharmacotherapy. However, the chemotherapy medication temozolomide has been increasingly used as a first-line treatment after initial evidence of its effectiveness in treating glioblastoma, the most common form of brain cancer.

In this study, researchers at the Jagiellonian University, in Poland, discussed the case of a 61-year-old man with ACTH-dependent Cushing’s syndrome caused by Crooke’s cell corticotropinoma.

The patient first presented with symptoms of severe hypercorticoidism — the excessive secretion of steroid hormones from the adrenal cortex — in December 2011. He also showed advanced heart failure, severe headaches, and impaired vision, which had started two or three years before diagnosis. Examinations revealed osteoporosis and a fracture in the Th5 vertebra.

His morning ACTH levels were high. The same was observed for mean cortisol levels even after dexamethasone treatment, which was suggestive of a pituitary tumor secreting ACTH. MRIs showed the existence of a tumor mass, later identified as a macroadenoma with high cell polymorphism, the presence of Crooke’s cells, and ACTH secretion.

The patient was referred for transsphenoidal nonradical neurosurgery, performed through the nose and the sphenoid sinus, and bilateral adrenalectomy, or the surgical removal of the adrenal glands, in 2012-2013. However, he developed fast, postoperative recurrence of hypercorticoidism and tumor regrowth. This led to three additional transsphenoidal neurosurgeries and radiotherapy.

The patient’s clinical status worsened as he developed severe cardiac insufficiency. Doctors began temozolomide treatment in April 2015, which did not result in adverse effects throughout treatment.

The initial standard dose (150–200 mg/m2) was given once daily in the morning for five consecutive days, in a 28-day cycle. The patient also received 600 mg of ketoconazole, an antifungal medication. Ondansetron was administered to prevent nausea and vomiting.

Subsequent examinations revealed clinical and biochemical improvements, including a reduction in ACTH and cortisol levels. In addition, the patient also showed reduced cardiac insufficiency, less frequent and less severe headaches, visual field improvements, and better physical fitness and mood.

However, clinical symptoms worsened after the eighth temozolomide cycle. The tumor size also suddenly increased after the ninth cycle, reaching the inner ear. Temozolomide was then discontinued and ACTH levels increased by 28 percent one month later. The patient also demonstrated deteriorated vision, hearing loss, and strong headaches.

Clinicians then decided to start treatment with the Cushing’s disease therapy Signifor (pasireotide), but a worsening of diabetes was observed, and the patient died in February 2016.

“The most probable reason for death was compression of the brainstem, which had been observed in the last MRI of the pituitary,” the researchers wrote, adding that “due to the very short duration of treatment, any conclusions on the treatment with Signifor cannot be drawn.”

Overall, “the results of the presented case suggest that [temozolomide] treatment monotherapy could have only partial response in aggressive corticotroph adenoma causing Cushing’s disease, followed by sudden progression,” the investigators wrote. This contrasts with mostly responsive cases reported in research literature, they noted.

“Therefore, further research on the factors of responsiveness and on novel methods to extend the duration of the effect of [temozolomide] should be carried out,” they wrote.

From https://cushingsdiseasenews.com/2018/02/08/cushings-disease-case-study-poland-shows-temozolomide-temporarily-effective-treating-aggressive-pituitary-tumor/

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